Isotopic alloys and articles thereof



March 8, 1966 D. A. MCCARTHY 3,239,333

ISOTOPIC ALLOYS AND ARTICLES THEREOF Filed Jan. 2, 1965 INVENTOR Donodd H. McCan hq 3 7 (R T@ ATTORNEYS United States Patent 3,239,333 llSOTOPIC ALLOYS AND ARTICLES THEREOF Donald A. McCarthy, Milford, Conn., assignor to Super Metals, Incorporated, New Haven, Conn., a corporation of Connecticut Filed Jan. 2, 1963, Ser. No. 249,077 6 Claims. (Cl. 75-153) This invention relates to articles formed of isotopic alloys of :metals and more particularly relates to isotopic alloys of copper and articles formed therefrom.

Natural copper is a mixture of essentially two stable copper isotopes, copper 63 and copper 65 which appear naturally in a well-established ratio to each other. Copper 63 comprises very close to seventy percent and copper 65 comprises very close to thirty percent of natural copper. The other isotopes of copper, which are radioactive together with traces of other metals, make up less than one percent of natural copper.

The present invention is based on the discovery that the electrical conductivity, heat transfer capability and also the corrosion resistance of copper may be improved by providing a new copper isotopic alloy comprising an unnatural combination of the isotopes of copper. As used herein, the terms isotopic alloy or alloy of isotopes as applied to copper refers to copper composed of isotopes of copper in an unnatural combination. The invention is also applicable to isotopic alloys of silver and articles thereof as will hereinafter be pointed out.

A primary object of the present invention is to provide isotopic alloys of copper which have improved electrical conductivity, thermal conductivity and corrosion resistance.

Another object of this invention is to provide electric conductors of improved conductivity.

Another object of this invention is to provide articles of improved thermal conductivity.

A further object of this invention is to provide articles of isotopic alloys of copper having an increased resistance to corrosion.

Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.

Briefly stated, the invention, in one form thereof, as it relates to copper, comprises copper isotopic alloys and articles formed thereof of increased electrical conductivity, thermal conductivity and corrosion resistance which predominantly comprises the isotope copper 65.

For a more complete understanding of the invention, reference should be had to the following text and the accompanying drawings wherein:

FIG. 1 illustrates, in section, a drawn conductor of an isotopic alloy embodying the invention.

FIG. 2 illustrates, in section, a conductor clad with an isoptopic alloy in accordince with the invention.

FIG. 3 illustrates a formed hollow article, such as a wave-guide made of an isotopic alloy in accordance with the invention.

FIG. 4 illustrates an article with a corrosion resistant coating of a copper isotopic alloy thereon in accordance with the invention.

The invention may best be disclosed and appreciated by consideration of a theory which is believed to explain the physical properties exhibited by compositions and articles formed in accordance therewith, together with a brief review of present theory.

Present theory The atom comprises a nucleus having a positive charge with one or more electrons thereabout. The atomic electron is pictured as a point charge orbiting the nucleus over various paths which produce a general cloudlike distribution of electron charge due to a probability distribution of these paths in time. The electron carries a magnetic field with it either by virtue of rotation about its axis or an eddy current phenomenon. Each electron has associated with it a wave-particle nature which permits the particle to enter only certain discrete energy states in the atom. When the particle electron goes from one energy level to another, radiation is either emitted or absorbed in the manner of a harmonic oscillator. The electron is considered a fundamental particle of nature and the various energy levels can be determined through an analysis of the radiation spectrum of the element it forms. Each element radiates a typical spectrum which identifies it and indicates the energy level of the electron or electrons present.

Each element has a typical number of positively charged particles, protons, in its nucleus which determines the charge of the nucleus; the nucleus also contains electrically neutral particles, neutrons, which contribute mass but not charge. Orbiting the nucleus, the electrons which are equivalent in number to the protons stack themselves in energy shells, including subshells, about the nucleus. The successive buildup of electron shells with electron additions produces the periodicity of the elements as represented in the standard periodic table chart.

The atomic structure of copper and its capacity to conduct an electric current varies through chemistry, physics, metallurgy, and conduction theory. However, the generally proposed idea is that it has one unpaired point charge electron orbiting outside several completed shells of electrons which surround a nucleus containing twenty-nine protons. The protons are responsible for the electrical charge of the nucleus, and the fact that copper is listed as the twenty-ninth element in the Periodic Table. From the nucleus outward, the first shell contains two 1s electrons; the second shell contains two 2s and six 2p electrons, and the third shell contains two 3s, six 3p and ten 3d electrons in the completed K, L and M shells, where s, p and d, with numerical coeflicients are the conventional symbols indicating energy states of electrons, and K, L and M are the conventional symbols from spectroscopy representing electron shells from the nuclues outwardly. The external electron is in a 4S orbit and is responsible for the 5 ground state energy level.

The completed inner shells are in a 8 state and do not effect the energy levels of neutral copper. Since copper has a chemical valence of 1 and 2, the last 3d electron is considered loosely bound and available for reaction.

For a more complete discussion of presently accepted theory of quantum and wave mechanics and atom structure, see Richtmeyer and Kennard, Introduction to Modern Physics, fourth edition. 1947, pp. 139-423, and White, Introduction to Atomic Spectra, first edition, 1934.

Postulated theory The theory postulated herein considers the atomic electron as an electromagnetic wave having particle properties and the electrostatic field emanating from the nucleus as originating from all the particles comprising the nucleus, i.e., neutrons as well as protons. Moreover, in the electrically neutral atom, the outermost electron shell is at a radial distance from the nucleus where the electrostatic field density, due to the charge of the nucleus, is unity or greater.

In order for an electromagnetic field or wave upon entering an electrostatic field to maintain its orthogonal relationship of magnetic to electric fields both in itself and to the electrostatic field, the direction of travel of the electromagnetic field must be deflected towards the source of the electrostatic field. If Faradays laws and Poyntings mathematics are true, it is concluded that an electromagnetic field or wave must be deflected when passing through an electrostatic field. In an electrostatic field of sufiicient strength, the travelling electromagnetic field will be deflected into a circular path around the static charge. The resultant destruction interference of the encircling electromagnetic waves results in a standing wave' which has the aspects of a particle. This particles has a spherical form which is an electromagnetic field travelling in a circle.

An atomic electronis the quantized resultant of all electromagnetic Waves circling the nuclear charge at a particular radial distance from the nucleus. The electron is a wave, with wave characteristics, of an amplitude which produces discrete levels at which the normal acceleration of each segment of the wave path tending to expand the wave is equal to the electrostatic attraction of the nucleus tending to contract the wave. The electron is a sphere or segment of a sphere of integral unit wave length in circumference, which envelops the nucleus either partially or fully depending upon its amplitude. Iti's divided in two by a polar plane through the nucleus which separates it into two magnetically opposed hemispheres or lesser spherical sections. The electron is magnetically polarized at the nodal points of the wave. It possesses orbital angular momentum by virtue of its circling impulse although it is a standing wave. It is not a fundamental particle of nature but is produced by the entrapment of electromagnetic fields by an electrostatic field emanating from the atomic nucleus.

The electron wave expands or contracts with the absorption or emission of radiation transforming itself into another resultant standing wave at a difierent discrete energy level. In a stable atom, one or more electrons can orientate themselves to form a shell enclosing the nucleus as long as their polar nodal points coincide. The resultant coupling moment of the angular moments of the electrons, the radial distance from the nucleus or electron wavelength, andthe amplitude of the individual waves, establish the resultant energy level for a particular shell.

Two electron waves can occupy the same path so long as they differ in either direction of travel or magnetic polarization or both. If the electron waves differ in both, the magnetic fields and orbital angular moment of the electron waves are neutralized and the electrons are inactive. In a two electron atom, such as helium, in the lowest energy level, the whole atom is chemically inert, i.e., will not form compounds. However, if one electron is moved to a higher energy level, the other electron immediately regains its activity.

The spherical shells increase in surface area with increase in radial distance from the nucleus. More and more electrons may occupy these increasingly larger shells. However, the electrons of one shell cannot overlap the electrons of an adjacent inner shell; consequently only alternate permitted shells can be occupied completely. Therefore, all inner shells are not necessarily completely filled.

The innermost shell, the K shell or kernel, as used herein, may contain a single electron wave of unit amplitude. It has an active magnetic field associated with it. In the first element, hydrogen, the atom contains only a single active unpaired electron which gives hydrogen a valence of one in equivalent chemical combinations. The magnetic field of the single electron will attract another electron and enter a transitory two-electron state which is responsible for the property of hydrogen bonding or bridging in complex organic molecules.

The single electron in the kernel is spherically symmetrical about the nucleus. The active fields of the electron provide a screen which nullifies part of the electrostatic field emanating from the nucleus. This screening of the charge of the nucleus by an active kernel electron reduces the effective charge of the nucleus external to the kernel. It effectively removes a single unit of charge contributing to the electrostatic field emanating from the nucleus consequently it acts as a shield or valve on the strength of the electrostatic field, due to the charge of the nucleus, external to the kernel.

The kernel can also contain two electrons of opposite travelling wave directions and with resultant zero amplitude and zero magnetic fields. The completed kernel is inert in both angular momentum and chemical atfinity. In helium, the first inert gas and second element, which contains two electrons, the kernal is filled in the lowest energy or quantum state which is a 8 state. The completed kernel with two paired electrons of zero amplitude and zero angular momentum is, in effect, spherically symmetrical about the nucleus because its periphery can not be penetrated from the outside without upsetting the electromagnetic and gyroscopic balance of the kernel electrons. Upsetting the balance of the kernel by mechanical or electromagnetic pressures causes the kernel electrons to uncouple and reappear actively. The completed kernel provides the base for further electron building in a radial direction away from the nucleus. With continued electron build-up, the diameter of the atom becomes larger and larger. The L shell builds up on the kernel or K shell but does not penetrate it.

The completed kernel is magnetically inert and does not screen the charge of the nucleus; consequently the total charge of the nucleus is effective external to the completed kernel. However, if the kernel is disturbed and loses one of its electrons due to capture by the nucleus or by transition to a higher orbit, the screening efiect of the kernel or external charge is immediately evident.

Inasmuch as the electrostatic or Coulomb charge emanating from the total nucleonic particles establishes the electrostatic field density at the various radial distances from the nucleus, the valving or shielding effect of the kernel is critical when the electrostatic field density established by the charge of the nucleus is unity at a particular radial distance from the nucleus. An inert kernel produc'es no shielding effect on the charge of the nucleus but a quantum transition of one electron in the kernel causes the electrostatic field density to drop below unity at this particular radial distance because of the screening or valving efiect of the resulting one electron kernel.

External to the K shell of permitted electron configuration, but internal to the skin or outer shell electrons in a many shell atom is the core as used in this discussion. In elements of lower atomic number the core and the outside skin of electrons may be identical if only two shells are present in the atom. In a three shell atom, the core is the single shell intermediate between the outer skin and the kernel. In a many shell atom the core may contain one or more shells.

The core comprises the L shell in a three or more shell atom. It may or may not have a kernel inSide it, depending on the wave amplitude and radial distance of the inner core electrons. At a unit radial distance of two from the nucleus, electrons cannot occupy the shell when a kernel is present because the overlapping electromagnetic waves would interfere. At a unit radial distance of three. electrons of unit amplitude will permit the exist ence of a kernel. At a unit radial distance of four, theelectron unit amplitude can become two and still permit: a kernel without interference with the electrons thereof. Six electrons, i.e., three pairs, can assume three oriented paths about a polar axis of the shell such that the parallel wave travel generates a wave unit amplitude of two in each path, but the gyroscopic couple produces a zeroresultant angular momentum for the three pairs.

The most often observed spectra predominantly result from transitions of core electrons. The lowest energy state core electron is the p electron with unit angular moment. The azimuthal orientation of the p electron with respect to the polar axis of the nucleus allows three 1 electrons to fill a subshell and three pairs to fill a shell. The d electron comes next with an orbital angular moment 55 of two. The azimuthal orientation of the d electron permits five a electrons to fill a subshell and five pairs to fill a shell. The gyroscopic coupling of the various electron momenta about the polar axis of the atom produces a resultant angular momentum for the whole atom.

Electrons of various azimuthal orientation about the polar axis are not limited in their radial distance i.e., their wave lengths, from the nucleus except in the lowest permitted shell for each particular azimuthal orientation. As the radius of the electron expands, it changes its wave characteristics and reappears at a larger radius and/ or different azimuthal orientation. This wave phenomenon is responsible for the so-called quantum transition or jump which divides the atom into various energy levels which are discrete. It is responsible for the particular aspect of absorption and emission in electromagnetic radiation from the material bodies.

Of particular interest in the present discussion is the innermost subshell of the core at a unit radial distance of two. In the elements, copper and silver, six I electrons at a unit radial distance of two and an amplitude of two form the lowest and innermost shell in these atoms in the electron configuration which is responsible for half the observed spectra of these elements. This kernelless configuration resembles the electron arrangement in the atoms of the elements immediately preceding copper and silver elements in the Periodic Table. Electron transi tions to higher levels result in so-called autoor preionization of the element. Transitions to these levels from higher levels produce the anomalous spectra of these elements.

When the six p electrons are at a unit radial distance of three, a single electron enters the kernel and produces the ground state of both copper and silver. The ground state or lowest state in the atom is a 5 state which is the final level in electron transitions from higher states copper and silver. In silver and copper, filling of the kernel with two electrons produces a vacancy in the d electrons at a unit radial distance of five, leaving nine electrons in the a shell. The kernel and p electron shells are filled in a paired configuration with zero angular momenta and zero amplitudes. In the absence of an internal screen, the d electrons are exposed to the total charge of the nucleus. Four paired d electrons have zero amplitude and the single unpaired electron is responsible for the angular momentum of the d shell and its unit amplitude.

The p electrons, intervening between the d shell and the kernel, afiect the energy levels in both silver and copper. Quantum changes in these atoms in the lower energy states are brought about by p electron transitions. When the p electrons enter a three pair alignment with active magnetic fields, the p electrons screen the nuclear charge and reduce the charge by six units external to the p shell. The p electrons thus have a valving or shielding effect similar to the kernel and aitect the radiation density of the electronic field due to the charge of the nucleus such that the electrostatic field density of uniy at a particular radial distance is reduced below unity.

As the electrons of the core build up on the completed kernel in completed shells of zero amplitudes, the total charge of the nucleus becomes more and more effective at greater radial distances therefrom. When the core and kernel are completely filled and at zero amplitudes, the total charge of the nucleus is exposed to the skin electrons. Residual charge external to the skin electrons imparts repulsion to adjacent atoms and causes translational motion and a change in state in a conglomeration of atoms such as a solid.

In metals, the electrons of the core are not in their lowest quantum level-s in the solid state. The physical properties of the metals are produced by electron configurations of the kernel and the core having angular momenta above zero, and active magnetic fields.

Postulated theory as applied to copper and silver In order to appreciate the general theory and conclusions as applied to copper and silver, consider the following discussion. An atom is composed of a nucleus with circumferential electron waves arranged in spherical shells at various radial distances. The individual electron waves occupy an entire shell or smaller segments of a shell. If the electron wave covers the entire spherical shell, it is spherically symmetrical about the nucleus and therefore contributes no angular momentum to the atom. It is in an S state with zero angular momentum. When the individual electron fills only a segment of a shell, it does so in discrete orientations about the polar axis of the shell. Depending upon the radial surface of a shell, one or more electrons can occupy the segments until the shell is again spherically symmetrical around the nucleus and again in an S state with zero angular momentum.

The smallest radial shell has a unit radius and provides one unit of radial surface area. It can accommodate an electron of unit amplitude or smaller. Since the electron is a wave, the smallest shell can contain two electrons travelling over the same orbital path in opposed directions of travel to produce a resultant wave of zero amplitude and zero angular momentum.

The smallest radial shell, the kernel, can contain one active electron with unit amplitude and zero angular momentum or two paired electrons with zero amplitude and zero angular momentum.

The next smallest shell can contain two electrons travelling in the same path and in the same direction to produce a resultant wave amplitude, two. It can also accommodate three electrons of unit amplitude or six paired electrons with zero amplitude or an amplitude of two. The combination of three waves, together with the angular momenta, enter a gyroscopic couple to produce zero, one or two units of angular momentum, depending upon their directions of travel. The amplitude of a single electron can be one; the amplitude of paired electrons either two or zero. In this discussion, the next smallest shell of a unit radial distance of two is the innermost shell of the atomic core.

The innermost subshells of the core number three and are at unit radial distances of two, three and four. However, in several shell atoms such as copper and silver, only one of these permitted subshells can be occupied completely at one time. The continued expansion of the wave amplitude from unity to two brings the three pairs of electrons to a unit radial distance of four. These electrons are the p electrons, i.e., each contributes unit angular momentum in the coupling scheme.

The external shell of electrons in this discussion is called the skin. The skin contains the valence electrons responsible for chemical atfinity in chemical reactions between atoms with active magnetic fields in the skin electrons. The skin establishes the diameter of the atom. If the electrons of the skin are inert, the skins of adjacent atoms overlap. In metals, for example, the skin electrons enter an exchange phenomenon with adjacent atoms so that the skin electrons lose their attachment to the individual atoms and become an electron fluid about the atoms comprising the metal.

The skin is located at a unit radial distance from the nucleus established by the Coulomb or electrostatic field emanating from the nucleus minus the screening elfects of the intervening active shells of the kernel or the core. has much as a minimum radiation density of unity is required to orbit electromagnetic radiation about a static charge, the radiation density at the skin is unity or greater. This is fundamental to the whole theory under discussion. A travelling electromagnetic field of radiation will be trapped into an electrostatic field surrounding a charge particle whenever the electrostatic field density (flux per unit area) emanating from the particle equals or exceeds unity along the path of the travelling field.

This condition is satisfied when the skin electrons are at a radial distance from the nucleus such that the ratio of the square root of the effective charge of the nucleus to the unit radial distance to the skin is unity or greater over the spherical surface of the skin, or otherwise stated, an electrostatic field density of unity occurs when the ratio of the eflfective charge of the nucleus to the square of the radial distance of the skin from the nucleus is unity.

The skin is built up on the last shell of the core, in atoms containing a minimum of three shells or more. In the solid state, the atomic electron configuration is produced by the number of skin electrons needed to neutralize the effective charge of the nucleus. Changes of state from solid through liquid to gas are produced as atomic electrons are reduced to their zero amplitudes and zero angular momenta with increasing extra atomic effect of the charge of the nucleus and increasing mutual repulsion between adjacent atoms resulting in translational motion of the atoms. Thermionic emission of skin electrons is produced by a such a process. The melting points of the elements of similar electron configuration are a rectilinear function of the square root of the atomic weights of the respective elemental solids because of the effect of the charge of the nucleus at the skin.

In silver, which has two stable isotopes, silver 107 and silver 109, the screening effect of the single kernel electron in the lowest ground state reduces the effective charge of the nucleus at the skin from the square root of 109, for silver 109, to the square root of 109 minus 1, or 108. Likewise for silver 107, the kernel electron reduces the effective charge of the nucleus to 107 minus 1, or 106. Since the radial distance of the skin in this 8 state is 10 radial units from the nucleus, the effective nuclear charge at the skin is in excess of unity and, therefore, the skin electrons are not critically bonded to the nucleus.

However, in silver 107, the next higher electron shell has six active p electrons which provide a screening effect which reduces the effective charge of the nucleus at the skin by 6 units. This electron configuration in silver brings the atoms of the isotope silver 107 down to an effective charge of the nucleus at 10 radial units to the square root of 107 minus 6 or the square root of 101, barely in excess of unity at a radial unit distance of ten from the nucleus. The electrostatic field density at the skin electrons approaches the critical value of unity and the skin electrons are easily detached to enter the exchange phenomenon of an electron fluid. A similar configuration in silver isotope 109 likewise reduces the bond of the skin electrons to the atom but not as close to the critical value of unity electrostatic field density.

The natural ratio of silver isotopes, silver 107 and silver 109, is closely fifty-two and forty-eight percent, respectively. Both isotopes are affected by the screening effects of the single kernel electron without any critical change in the effect of the charge of the nucleus at the skin. However, silver 107 is considerably affected by the active p electrons which reduce the effect of the charge of the nucleus to a minimum at the skin. Silver 109 is also affected but not to this critical extent. Therefore, silver 107 is a better conductor of electricity than silver 109.

In copper, the screening effect of the single kernel electron in the lowest ground state S reduces the effective nuclear charge by one, as in silver. In isotope copper 63, the effective nuclear charge at the unit radial distance of seven is reduced to the square root of sixty-three minus one or the square root of sixty-two which increases the electrostatic density at a radial unit distance of seven from the nucleus, and thus bonding of the skin electrons to the atom. The active p electrons provide a further screen and reduce the effect of the charge of the nucleus further but not sufficiently to reduce the electrostatic field density at the skin to unity. Consequently the isotope copper 63 is the least conductive of the electrical conductors in the present discussion of silver and copper isotopes.

Copper 65 is critically affected by the screening of a single kernel electron. At a skin radial unit distance of eight, the effective charge of the nucleus is the square root of sixty-five minus one, or the square root of sixty-four. Thus, the electric field density at a radial unit distance of eight from the nucleus is unity, the least radiation density capable of bonding an electron in an atom. Furthermore, the transition of an electron in and out of the kernel causes a change of critical electric field density at the skin. The appearance of active p electrons reduces the effective electrostatic field due to the nuclear charge below unity at radial unit distance eight and completely unbonds the skin electrons from the nucleus. Copper is an excellent conductor of electricity because of its extreme sensitivity to electromagnetic fields which Will produce a quantum transition from its lowest state.

The natural ratio of copper 63 and copper 65 are closely and 30%. However, unlike silver, one of the isotopes, copper 63, is affected adversely by the screening effect of the electron shells. This isotope makes up the major portion of natural copper. The natural silver mixture is therefore a better natural conductor than the natural copper mixture.

The conductivity of a metal is established by its electron population, that is, the number electrons capable of travelling through the metal under an applied electric field. The skin electrons of the constituent atoms provide these electrons and consequently the loosely bound electrons can enter the electron fluid of the metal crystal with the least required energy absorption by the atom.

The number of electrons in the skin establishes the number of electrons available to enter the exchange phenomenon of an electron fluid in a metal crystal.

In silver, the skin electrons number eighteen. In copper, the skin electrons number fourteen in copper 63 and sixteen in copper 65. Silver contributes more electrons per atom than copper and therefore has a higher electron population. Copper 65 requires the least amount of absorbed energy to produce the greatest effect on the skin electrons, so copper 65 contributes the greater number of free electrons under an applied external electric field. Depending upon the energy level distribution of the atoms in copper 65 versus those in silver 107 as determined by ambient temperatures surrounding the two metals, copper 65 is the best conductor at lower temperatures and silver 107 at higher.

Corrosion is an electrochemical phenomenon. All corrosion processes require a driving potential difference to transport electrons in an oxidation process. Residual nuclear fields of adjacent atoms can produce a difference of potential in localized areas on a metal surface. This is particularly obvious when a metal surface is contaminated by extraneous materials such as has been observed with purified aluminum. In isotopic mixtures such as found naturally in copper and silver, but absent in gold, the adjacent atoms have different residual nuclear fields and consequently can establish a potential difference along the metal surface.

In copper 65, the residual electrostatic field due to the charge of the nucleus is close to zero and the adjacent atoms are in close contiguity. A reaction with oxygen is prevented by the absence of potential difference along the surface. The crystal interstices between the closely packed atoms prevent the oxygen from kinetically entering the crystal. A similar condition exists for silver 107 and to a lesser degree silver 109. Copper 65 will approach gold in nobility.

The superior corrosion resistance of copper 65 was evidenced by a comparative test of pellets of copper 65 and copper 63.

A one gram pellet of copper 65 of 99 percent isotopic purity, flattened into a coin shape .040 inch thick and approximately one-half inch in diameter, and a similar pellet of copper 63 of 99 percent isotopic purity were each placed in separate glass vials having loose fitting caps. The pellets were left in the vials for a six month period except for removal for examination for oxidation. In this six month period, the pellets were equally exposed to a normal household atmosphere, except for a four week period during which they Were stored in an industrial shop atmosphere. Clean white cotton gloves and tweezers were used in handling the pellets to prevent extraneous contamination of the pellets. The pellets received equivalent handling, care, treatment and exposure to minimize experimental error.

It was observed that oxide began to noticeably discolor the copper 63 pellet after four weeks. After six months the copper 63 pellet Was completely covered with oxide and darkened to a normal copper oxide color. In contrast, the copper 65 pellet, throughout the six month test period, remained bright and golden in appearance.

In adition to the aforementioned comparative test of copper 65 and copper 63, three flattened pellets of high purity (99.99 percent) natural copper of equal area, thickness and weight were exposed to a normal household atmosphere for a period of four months. These pellets were observed to have noticeable oxide discoloration within the initial four weeks of the four month period. This oxide discoloration continually increased during the total four month period.

The thermal conductivity of a material, that is its ability to conduct heat, is determined by the ability of the individual atoms in the material to transfer kinetic motion. The atoms in a metal crystal are oriented in various crysstalline structures. Aluminum, copper and gold have face-centered crystal lattices with atoms arranged in contiguous layers. Any motion imparted to a particular atom is transferred directly to adjacent atoms.

Atoms which have core and kernel electron shells in a state above zero in wave amplitude in angular momentum are sensitive to applied pressures. Kinetic impact from an external source alters the dynamic balance in such shells and produces a quantum transition to a lower electron state. The increased residual nuclear charge resulting from this transition repels the next adjacent atom which repeats the process. In copper 65, the change in energy level of the inner electrons under a kinetic impact type pressure Will produce the greatest change in the residual nuclear charge as explained above. It is possible to increase the residual atomic charge from slightly above unity at radial distance eight to considerably above unity at radial distance seven. This discussion shows copper 65 to be the best conductor of heat of the four isotopes discussed.

In accordance with the invention copper isotopic alloys and articles thereof are provided which have increased electrical conductivity, heat conductivity and corrosion resistance.

A conductor comprising a drawn wire 10 of an isotopic alloy of copper comprising predominantly copper 65 and the remainder copper 63 is illustrated in FIG. 1.

FIG. 2 illustrates a conductor 11 comprising a core 12, which may be of steel for structural reasons, with a cladding of a copper isotopic alloy predominantly comprising copper 65. By predominantly comprising is meant at least ninety percent copper 65 with the remainder being other isotopes of copper or copper as found in natural form.

FIG. 3 illustrates a formed hollow or tubular article 14 such as a Wave guide formed of predominantly copper 65 (at least 90 percent copper 65) with the remainder being other isotopes of copper, mainly copper 63, or natural copper.

Other articles which might be manufactured utilizing the invention include but are not limited to heat sinks and circuit boards having conductive patterns of copper thereon.

FIG. 4 illustrates an article 15 having a corrosion resistant cladding or coating 16 of a copper isotopic alloy or copper alloy comprising 90 percent copper 65. A corl0 rosion resistant cladding or coating of ninety percent copper may be coated, plated or otherwise deposited on various devices such as electrical contacts to prevent oxidation of contacting surfaces. Additionally, copper 65 isotopic alloys may be used as a decorative coating of articles such as plaques, statues, lamp base, etc. In non-electrical application copper isotopic alloys containing 90 percent copper 65 may be alloyed with other metals to improve the corrosion resistance thereof.

It is to be understood that the invention also includes isotopic alloys of silver containing predominantly silver 107, where such isotopic alloy comprises essentially at least ninety percent silver 107 or more, with the remainder being silver 109. However, it is contemplated, due to the cost of silver, that such isotopic silver alloys would principally be used in electrical applications such as waveguides, as illustrated in FIG. 3.

Copper 65 may be obtained by separation of the isotopes of copper as found in natural copper and redeposition of the isotopes in an unnatural combination comprising ninety or more percent copper 65 with the remainder made up principally of copper 63. The separation may be accomplished for example by diffusion methods utilizing chambers, by mass spectrograph, or by differential melting or other methods, which will produce copper with a ninety percent or better content of copper 65. Silver 107 may be obtained from natural silver by the same techniques.

While specific articles and applications thereof utilizing the invention have been set forth for purposes of disclosure, other uses, applications and forms thereof may occur to those skilled in the art which do not depart from the spirit and scope of the invention. Accordingly, it is intended to cover in the appended claims all articles and compositions embodying the invention which do not depart from the spirit and scope of the invention.

What is claimed is:

1. A copper alloy containing isotopes of Cu and Cu consisting essentially of no more than 10 percent copper 63 and the balance essentially copper 65 2. A copper alloy containing isotopes of C1163 and Cu consisting essentially of no more than 10 percent copper 63 and the balance copper 65.

3. An article of manufacture composed of a copper alloy containing isotopes of Cu and Cu consisting essentially of no more than 10 percent copper 63 and the balance essentially copper 65.

4. As an article of manufacture, an electric conductor composed of a copper alloy containing isotopes of cu and Cu consisting essentially of no more than 10 percent copper 63 and the balance essentially copper 65.

5. As an article of manufacture, a thermal conductor composed of a copper alloy containing isotopes of Co and Cu consisting essentially of no more than 10 percent copper 63 and the balance essentially copper 65.

6. An article of manufacture composed of a copper alloy containing isotopes of Cu and Cu consisting essentially of no more than 10 percent copper 63 and the balance essentially copper 65 References Cited by the Examiner UNITED STATES PATENTS 2,854,332 9/1958 Bredza et al. -153 2,923,620 2/1960 Bulow 75153 2,932,569 4/ 1960 Buchinski et al 75173 2,935,401 5/1960 Anderson et al 75173 OTHER REFERENCES Excitation Functions for Proton-Induced Reactions With Copper, by I. W. Meadows, Physical Review, vol. 91, ser. 2, Aug. 15, 1953, pp. 885-889.

DAVID L. RECK, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,239,333 March 8, 1966 Donald A. McCarthy It is hereby certified that error appears in the above mmberod patent requiring correction and that the said Letters Patent should read as corrected belw.

Column 2, lines 43 and 44, for "nuclues" read nucleus column 3, line 5, for "destruction" read destructive column 4, line 10, for "kernal" read kernel column 5, line 36, after "states" insert which produce the normal doublet spectrum in both line 57, for "electronic" read electrostatic line 58, for "uniy" read unity Signed and sealed this 24th day of January 196?.

Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents 

1. A COPPER ALLOY CONTAINING ISOTOPES OF CU63 AND CU65 CONSISTING ESSENTIALLY OF NO MORE THAN 10 PERCENT COPPER 63 AND THE BALANCE ESSENTIALLY COPPER
 65. 